Combining two different networks using VSS

[deepak george]

Hello ALL, My office is spread across two different buildings adjacent to each other.However we have separated them into two different networks. i.e Building-1 10.10.0.0/16 10.20.0.0/16 The architecture is more like any other network with Internet Router-Firewall-Core-Distribution-Access. Building-2 10.40.0.0/16 10.50.0.0/16 The architecture is same as building 1 Here the Internet traffic flows separately across both the buildings. We also have 8 fiber links terminated between both the buildings for the connectivity between Building-1 and Building 2. I was hoping to change this setup wherein we run VSS with Active in Building-1 and Standby in Building-2. What will be the challenges involved in such a scenario... Thanks

[Reza Sharifi]

Hi,

The challenge for the design you are proposing is that every access switch now has to be able to reach both buildings and having only 8 fiber pairs most likley is not enough.  Out of 8 fiber pairs you need 2 for VSL link and one for fast-hello.  So by the time you are done with VSS config, you only have 5 pair left. Is that enough to uplink your access switches to both buildings?

HTH

[deepak george]

Hi Reza,

I am a very big fan of yours and keep reading your posts.

I missed out the point which you have told... Is there any other option of making both the networks as ONE other than going for VSS as we will have to procure the hardware.. So i am looking at a best practice to keep te network simple and redundant....

[Reza Sharifi]

Hi Deepak,

Thanks for the kind words!

Yes, defiantly there are options.  One good option is to add more fiber links between the 2 buildings. So it depends on the number of closets with access switches.  If you have say 6 closets per building and each with 1 switch in it than you need at least 12 pairs of fiber just for that. This is assuming you only want 2 uplinks per switch, but if you need more uplinks than you need more fiber.

How may access switches do you have in each building and how many uplinks do you want to have per switch?

HTH

[deepak george]

Hi Reza,

Thanks for getting back on the same.

We have close to 25 access switches in each building,hence adding more fiber between the buildings would add up to a lot of cost and managing these might be very tough too. So i believe that VSS would not be a great option to run in my environment. I may still have to proceed with the existing setup of having two networks across two different buildings.

However i am looking for some scope wherein i can improve the infrastructure.

Thanks for your help

[Reza Sharifi]

Hi Deepak,

With 25 access switches per building, I think it is good idea to have the type of setup you have where the core switches are local to each building. This setup will give you the local connectivity you need and you don't have to go over fiber backbone to cross to the other building to reach the default gateways. If you can provide more info and maybe a drawing, I maybe able to provide you input to improve the infrastructure.

HTH

[deepak george]

Hi Reza,

Thanks for being so kind to me. 

Please find the diagram attached.

We are planning to revamp our infrastructure. We are using pretty old devices. We would like to change everything which can be cost effective. We are using dual SUP's in the chassis switches.

Would request you to help me with your inputs

Thanks for your help....

[deepak george]

Hi Reza,

Waiting for your inputs...

Thanks